Motor control.



W. NAUMANN.

MOTOR CONTROL. APPLICATION FILED AP R.14, 1910.

Patented July 2, 1912.

2 SHBETSSHEET 1.

Mfsfittorney h. FE. OWM [CV2 m m mm M W l/i i tnesses:

W. NAUMANN. MOTOR-CONTROL.

APPLICATION FILED APR.14, 1910.

1,031,573, Patented July 2,

2 SHEETS-SEEET:

/r7 ven tor W/lhe/m Naumann,

H/sAttorney UNITED STATES PATENT OFFICE.

WILHELM NAUMANN, F PANKOW, GERMANY, ASSIGNOR TO GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

MOTOR CONTROL.

' Specification of Letters Patent.

Patented July 2.1912.

Application filed April 14, 1910. Serial No. 555,440.

To all whom it may concern:

Be it known that I, WILHELM NAUMANN, a subject of the Emperor ofGermany, residing at Pankow, Germany, have invented certain new anduseful Improvements in Motor Control, of which the following is aspecification. v

My invention relates to the ,control of electric motors driving planersor other machines having a reciprocating movement.

It is the object of my invention to provide a novel and simplearrangement of the controlling system and of the automatic means foractuating them to stop, reverse and accelerate the motor as the machinefinishes its travel in each direction.

For motors of any size which drive reciprocating loads and which arestopped and reversed periodically, it is necessary to employ a startlngresistance, because, 1f

the motor were reversed without resistance tromagnetically actuatedmotor starters in.

such a manner that one of them makes the connections for forward drivingand the other for backward. There ,are also well .known in the artregulating devices which starting.

have separate reversing and switches which are moved by the drivingmechanism through magnetic or friction clutches. The first mentionedarrangement of two complete 'electromagnetically actuaied startersrequires a large amount of apparatus and the starting period does notadapt itself to varying loads if the retardation of the movement of thestarter is uniform. For different loads the momentum is different andwith a starter operating umformly the motor is sometimes over worked inreversing and at other times the reversal takes longer than it should.Thesecond arrangement, that of having a mechanically actuated reversingswitch and a separate starting switch, ordinarily has the disadvantagethat the starting resistance for by the load for actuating the motorcontrolling switch cont-acts as the loadapproaches the end of its travelin either direction to stop and reverse the motorand means driven by theload for actuating the switch contacts upon the beginning of the returnmovement to accelerate the motor.

My invention will be understood by reference to the followingspecification taken in connection with the accompanying drawings, inwhich Figure 1 shows diagrammatically motor controlling means arrangedin accordance with my invention; Fig. 2 shows diagrammatically anotherform of embodiment of my invention; Figs. 3, 4 and 5 show the devices ofFig. 2 in the different positions 00- cupied during the reversal of themotor: Fig. 6 shows a plan view of the devices of Fig. 2; and Fig. 7shows still another form of embodiment of my invent-ion.

In Fig. 1 a reversing device is shown in which the switch member 1- forreversing the motor is separated from the switch member s which controlsthe resistances w for starting the motor.

a represents the armature of the motor and f its field.

In the drawing the starting device is shown in a position whichcorresponds to the backward operation of the machine at full speed, whenthe resistance w is entirely out out of circuit. It is assumed that theswitch .9 tends to take its lower position by gravity but is held in theposition shown by 106 means of an electromagnet b with its armature c aslong as the electromagnet, connected in series with the motor armaturea, is. excited. The reversing switch 1 is supposed to remain in anyposition to which it is 105 moved. Upon the driven machine, as forinstance the planer, are placed two adjustable carriers F and B uponwhich are a series of inclined planes at, to d, which cooperate with therollers e and 6 connected to 110 the reversing switch 1- and thestarting switch 8 respectively.

The method of'operation toward the end of the backward movement is asfollows: As soon as the inclined plane d of the carrier B engages theroller 6, the reversing switch 7 is raised from the position. shown toits other position so as to reverse the armature connections of themotor.

In passing from one position to the other, the switch 0" opens the motorcircuit so that magnet b is deenergized and releases its armature 0allowin-gthe starting switch s to drop to its lowest position. Thecontinued movement of the machine'while the switch-r is moving throughits mid or off position is due to the momentum of the machine and of themoretards, stops and reverses the motor.

resistance w is of sufficient amount to llmlt tor. When the switch 7"reaches its other position the motor is reversely connected to thesource with all theresistances w in \se ries with the armature and areverse torque is consequently produced in the motor which The thecurrent to its proper value during this operation. After the motor hasstarted to drive the machine forward on the return stroke, the inclinedplane (Z engages the roller 0 and raises the switch 8 so as to cut outthe resistance "20 gradually. When the' switch s is returned to theposition shown in Fig. 1, it held in that position by the electromagnet(Z until the machine reaches the other limit of its travelwhen a similaroperation of the switches take place by means of the inclined plane (Zand (Z Y If it is desired to provide for a possible interruption of thecurrent while the ma chine is in the middle of its travel, which wouldcause the switch sand roller 6 to drop to their lowest positions,additional in clined planes may be provided as indicated at-(Z, and d tolift the roller e out of the way of the members (i and 113 Figs. 9. to 6show another form of embodiment, only the starting and reversing con-'tacts instead of being separated are combined 1n a'smgle switch K. The0E posi; tion of this switch 15 in the m ddle, as shown in Fig. 6, wherethe contacts are indicated on a plane surface. On opposite sidesof theoff position are starting, accelerating and 7 running positions foropposite directions of rotation. The four upper contacts are thereversing contacts and the three lower the.

starting contacts. The adjustable carriers Fand B on the driven machinecarryactu- 'ating members d, to 45,, as in Fig. 1, but in Fig. 2 themembers al a, are not inclined I on their actuating surfaces, whilethe'members Z (Z; are bothpii'oted. The switch K which is of therotaryfirum type is provided with three arms 6 e 2 The member (Z,actuates the arm 6 the member 03 actuatesethe arm c and the arm 6 isactuated.

.by both the members d, and (Z different speeds are desired for forwardand backwardmovement the arms 6 and 6 may be pr different lengths asshown.

Fig. 2 shows the-starter in position for full backward travel. Themember d approaches the arm 0, until the, two meet and the starter isthen rotated from its running position for backward rotation throughitson its pivot to permit the roller to pass. As

soon as the momentum has beenovercome,

the machine is driven forward and the mom-- ber (Z is brought intoengagement with the roller (3 As the roller moves over this member, asshown in Fig. 5, the movement of the starter is continued from the firststarting position through the accelerating to the running position sothat the loadis automatically accelerated. In similar manner thereversal from forward to back-wardmovement is accomplished at the otherend of the limit of travel of the machine.

In Fig. 7 is shown still another embodiment which is similar to that of,Figsl2'to 6, except that'onlya single roller e? is em ployed. Themovable switch member is is shown as comprising a pivoted arm; In thisfigurethe starter is shown in the position in which thela dju'stablecarriers]? and- R are moving forward at full speed. As

the limit of travel is approached, the memw her (i, is brought. intoengagement. with roller 6 as indicated in dotted lines and the roller iscarried downward by traveling along the under surface of this memberKuntil the switchyar'm la has-been. moved Ythrough the mid or offposition to the first starting position on; the'other side ofl ofi'.position. When the backward movement begun the roller strikes the undersurface of the member d the-roller is pushed farther downand the'switcharm'k is moved gradually to the full runni position for backwardrotation. At the oter c'nd ofthe;

stroke the switch] arm is returned to the? position shown by'a similarseries of oper-' ations. 'In order to shorten the time of reversal themember (1 is pivoted so as th' allow the roller to pass beneath it' asthe .machine, approaches the'end of its stroke. By means of thisarrangement the member d may be made to engage the rollermorepromptlyafter return movement. has begun than'is possible if the member,is-fixed. as

shown at d versal is less.

I d'onot desire to limit myself to the particular construction andarrangement of parts shown and described but aim in "the appendedclaims'to cover all modifications which are within the scope of myinvention.

What I claim as newand desire to secure by. Letters Patent of the UnitedStates, is,-

1. In combination and reciprocating load driven thereby, switch contactsfor starting and reversing the motor, said reversing switch contactshaving a mid position in which the motor circhit is open, and two pairsof actuating members driven by the load for engaging and actuating saidswitch contacts at opposite ends of the travel" of the loadrespectively, one actuating member of each pair engaging and actuatingthe switch contacts as the load approaches the end of its travel so thatthe time used for reto move the reversing contacts from one runningother running position and the starting contacts from running positionto first starting position, whereby the motor is given a reverse torqueto stop and toreverse the load, and the other actuating member of thepair engaging and actuating the switch contacts as the load begins itsreturn movement to move the starting contacts from first startingposition to running position, whereby the return movement of the load isgradually accelerated. I

'2. in combination with an electric motor and a reciprocating loaddriven thereby, switch contacts for starting and reversing the motor,and two pairs of actuating mem- 'iers driven by the load for engagingand actuating said switch contacts at the opposite ends of the travel ofthe load respectively, one actuating member of each pair engaging andactuating the switch contacts as the load approaches the end of itstravel to stop and reverse the. motor, and the other member of the pairengaging and actuating the switch contacts as the load begins its withan electric motorposition through off position to the return movementto, accelerate the motor, the last mentioned member being movable in onedirection on its support so as to yield and-to pass the switc contactswithout actuating them as the load is approaching the end of its travel.

3. In combination with an electric motor and a reciprocating load driventhereby, a combined starting and reversing switch for the motor havingan ofi posit-ion and starting, accelerating and running positions onopposite sides of off position for opposite irections of rotation, meansdriven by the load for moving said switch from runnin position to thestarting position on the other side of off posit-ion when the loadapproaches either end of its travel, and means driven by the loadforcontinuing the move ment of the switch to accelerating and runningpositions when the load has begun its return movement. i

4. In combination with an electric motor and a reciprocating load driventhereby, a combined starting and reversing switch for the motor havingan off position and starting, accelerating and running positions onopposite side of off posit-ion for opposite directions of rotation, andtwo pairs of actuating-members driven by the load for en'- gaging andactuatingsaid switchat opposite ends of the travel of the loadrespectively, one actuating member of each pair engaging the switch asthe load approaches the end of its travel and moving it from runningposition to the starting positionon the opposite side of off position,and the other member of the pair cugaging the switch as the load beginsits return movement and continuing the movement of the switch to theaccelerating and running positions; In witness whereof, I have hereuntoset my hand this 24th day of March, 1910.

WILHELM NAUMANN. Witnesses:

LEOPOLD JANISCH, FRIEDRICH EIoHBY.

